Slide fasteners



Sept. 18, 1962 TADAo YosHlDA SLIDE FASTENERS Filed Jan. 15, 1960 mmmmm mwmmmmmlwmmwm mmmmmmmm mmm mmm m United States Patent O 3,054,158 SLIDE FASTENERS Tadao Yoshida, 339/2 Suwacho, Ichikawa-shi, Chiba-ken, Japan Fires Jan. 1s, 1960, ser. No. 2,621 Claims priority, application Japan Dec. 8, 1959 2 Claims. (Cl. 24-205.1)

This invention relates to slide fasteners and particularly to those comprising a pair of U-shaped continuous engaging elements operated by a slider member movable: between them to open and close an opening of garment, container or the like.

In usual slide fasteners having U-shaped continuous engaging elements, the engaging element having a series of U-shaped legs is applied to a woven or other flexible base tape along its longitudinal edge with the U-shaped legs striding the tape edge, and the legs on both sides of the tape edge are covered by narrow tapes, respectively, and secured to the base tape by stitching them up together with threads. If there is or occurs any local default in the stitching, the legs in such location are caused to lose alignment with the whole series of legs, resulting in misalignment of the engaging portions of cooperating pair of engaging elements. This makes opening and closing operations difficult or not smooth, and in addition, accelerates spoiling of the slide fastener.

In order to overcome these disadvantages, the usual slider member is provided with projecting ribs on the front and rear walls of its body for maintaining the alignment of engaging elements. For this purpose, however, the slider body must have relatively thick front and rear walls, which, together with the narrow tapes covering the series of legs, form rather a thick inward projection, so that the movement of the slider may be obstructed by contents of fully loaded container, or in case of underwear, the slider may give uncomfortable feeling to the wearer. In addition, the appearance of slide fastener is not good because of undue projections.

The main object of the present invention is to improve the slide fastener of the kind specified, by providing positive means for securing the engaging elements to the base tapes, without increasing the whole thickness of slide fastener and without producing undue inward projection of the slider body.

Other objects and particularities of the presen-t invention will be made obvious by the following detailed description of preferred embodiments of the invention shown in the accompanying drawings, in which;

FIG. 1 is a front elevational view of a portion of a slide fastener embodying the invention, partly broken away;

FIG. 2 is a back elevational view of the slide fastener shown in FIG. 1, partly broken away;

FIG. 3 is a side elevational view of the slide fastener shown in FIGS. 1 and 2;

FIG. 4 is an enlarged cross-sectional view of the slide fastener im :closed position, the section being taken through the slider;

FIG. 5 is a sectional View similar to FIG. 4 of a modified form of the invention.

Referring to the drawings, a pair of base tapes 1 are provided and characterized in that each tape has a bifurcated edge having two, front and rear, parallel branches 2 and 3 formed integral with the body of tape. The tapes may be woven or otherwise made originally in such forms.

A known U-shaped continuous engaging element, having a series of engaging portions 4 and intermediary U-shaped legs A and A', is applied to the front branch 2 of each tape 1, with U-shaped successive legs A and A striding the branch 2, and the bights C of the Us 3,054,158 Patented Sept. 18, 1962 ICC abutting yagainst the bottom B of the groove formed by branches 2 and 3. A narrow tape or web 5 is then applied on the front side series of legs A', and branches 3 and 2, legs A and A', and web 5, all are stitched up together by thread t. The series of rear legs A embraced between branches 2 and 3 are positively secured thereby with substantially no tendency to tilt or twist, and the whole engaging element is properly Xed to the base tape 1, resulting in accurate and smooth engagement of the cooperating pair of engaging elements. In addition, it is not necessary to apply separate covering tape onto the rear side series of legs A.

The two branches 2 and 3 may be formed in a forklike cross-section as shown in FIG. 4, or with the rear branch `3 at with the tape body while the front branch 2' rising from the tape body as shown in FIG. 5.

According to the present invention, the body of slider 6 for operating the pair of engaging elements has a front wall of usual construction having a usual rib and a rear wall 7 which is not provided with any operating rib and consequently is at and rather thin as shown in the drawings. Thus, the slider according to the present invention does not offer any undue inward projection discussed as previously.

`I claim as my invention:

1. A slide fastener comprising a pair of base tapes, each having a front and rear surface and a bifurcated longitudinal edge including a front and rear branch, the rear branch having a surface facing the front branch which surface is coplanar with the rear surface of the tape, a U-shaped element on each said tape adapted for engaging one another, each said U-shaped element including two legs, one of said legs being sandwiched between the front and rear branch of the corresponding tape, the other of said legs being supported on the front -branch of the tape so that the U-shaped element is supported by the tape `and extends only frontwardly from said coplanar surfaces whereby the rear surface of the tape is relatively flat, a relatively thin tape supported on the other of said legs of said U-shaped element to cover the same, and a slider enclosing said branches and U- shaped elements and substantially coplanar with said rear surface of the tape, said slider being displaceable along the longitudinal edge of the tape for engaging and disengaging said U-shaped elements.

2. A slide fastener comprising a pair of base tapes, each having a front and rear surface and a bifurcated longitudinal edge including a vfront and rear branch, the rear `branch having a surface which is coplanar with the rear surface of the tape, a U-shaped element on each said tape adapted for engaging one another, each said U-shaped element including two legs, one of said legs being sandwiched between the front and rear branch of the corresponding tape, the other of said legs being supported on the front branch of the tape so that the U- shaped element is supported by the tape and extends only frontwardly from the rear branch so that said surface of the tape is planar, a relatively thin tape supported on the other of said legs of said U-shaped element to cover the same, and a slider enclosing said branches and U-shaped elements and substantially coplanar with said rear surface of the tape, said slider being displaceable along the longitudinal edge of the tape for engaging and disengaging said U-shaped elements.

References Cited in the le of this patent UNITED STATES PATENTS 2,316,787 Gould Apr. 20, 1943 FOREIGN PATENTS 551,821 Belgium Nov. 14, 1956 447,000 Great Britain May 11, 1936 

